RESIDUES IN VARIOUS TISSUES OF STEERS FED 4-AMINO-3,5,6-TRICHLOROPICOLINIC ACID

Nine young steers were fed the potassium salt of 4-amino-3,5,6-trichloropicolinic acid for at least 2 weeks at rates from 200 to 1600 p.p.m. in the total diet, equivalent to 2.6 to 23 mg. per kg. per day at time of sacrifice. Blood levels were determined frequently throughout the experiment. To obtain tissues for analysis, eight animals were slaughtered while on the chemical, while one was sacrificed after a 3-day withdrawal period. The concentration of the compound in blood reached a maximum within 3 days after feeding was begun and decreased rapidly after withdrawal. Residues in tissues from animals slaughtered without a withdrawal period were proportional to concentrations fed: <0.05 to 0.5 p.p.m. in muscle and fat, 0.12 to 2.0 p.p.m. in blood and liver, and 2 to 18 p.p.m. in kidney. These decreased to <0.1 p.p.m. in kidney and <0.05 p.p.m. in all other tissues within 3 days after withdrawal from the highest feeding level. © 1969, American Chemical Society. All rights reserved.